First, you're not mental or retarded. There's strong research that shows it's due to differences in the way your brain developed. Psychology affects it but it doesn't cause it. Next, get a speech pathologist that specializes in stuttering. You can still be a kick ass communicator. You'll need lots of confidence and strength and a good speech path can help you figure it out. It sucks growing up with this. Try not to do it alone. Look up Friends (Youth National Stuttering Association) and SAY (stuttering association for the young)